A new electrochemical device holds potential to directly split carbon dioxide (CO2) into carbon and pure oxygen. The team from Nanjing University in China states that this technique could prove ...

The findings also suggest oxygen may not be a permanent biosignature on habitable planets, impacting the search for extraterrestrial life.

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. The Mars Oxygen In ...

which is why CO2 levels, not oxygen levels, generally trigger the urge to breathe. "But in marine mammals, you don't really see an increase in CO2 in the blood, because they have ways to ...